Polymerization of such as alkylene oxide compounds to give high-molecular polymers and copolymers has been known for a long time, and the number of the bibliographies about this subject amounts to several hundred. The polymerization of the alkylene oxide is conventionally carried out using the wide range of catalysts as based on metal atoms which include oxides and/or hydroxides of transition metals such as iron and metals such as magnesium, aluminum, zinc, and calcium. U.S. Pat. No. 2,971,988 (issued Feb. 14, 1961) discloses an amide/metal alkoxide catalyst as based on calcium and reformed with ammonia. However, such a catalyst frequently leaves a formed polymer which has unpleasant smells of ammonia and amines, and those unpleasant smells are difficult to remove. Moreover, there are problems in that the operation of preparing the catalyst is complicated, and in that if no post-treatment such as heat-aging is performed, it is hard to obtain catalytic activity.
In addition, on the other hand, zinc catalysts are also researched. For example, JP-B-45-007751 and JP-B-53-027319 disclose that a product, as obtained by reacting a monohydric alcohol upon a product from a reaction between an organozinc compound and a polyhydric alcohol, or by reacting a polyhydric alcohol upon a product from a reaction between an organozinc compound and a monohydric alcohol, exhibits excellent catalytic activity to homopolymerization of an alkylene oxide or copolymerization of two or more alkylene oxides, thus giving a polymer with a high degree of polymerization. However, it is pointed out that the above conventional processes have problems in that the reproducibility, for example, of the polymerization rate and the degree of polymerization of the resultant polymer, is bad, and the sufficient yield cannot be obtained, or the polymerization product is lumped, so the polymer cannot industrially stably be produced. Furthermore, the degree of polymerization is still not sufficiently satisfactory.
On the other hand, a process is attempted to obtain a polymer with good reproducibility by using a catalyst comprising a product from a reaction between an organozinc compound and a polyhydric alcohol, which reaction is carried out under conditions where various fine particle metal oxides (dispersion promoters) and nonionic surfactants are in contact with each other in an inactive medium (EP 239,973 and U.S. Pat. No. 4,667,013). However, it is pointed out that this process has disadvantages in that the operation of preparing the catalyst is very complicated. Specifically, because no reversed micelle is formed in spite of the use of the surfactant, a long-time stirring is needed for dispersing a polyhydric alcohol such as 1,4-butanediol into a hexane solvent wherein the polyhydric alcohol is insoluble in the hexane solvent, and further, the stirring conditions need high technique and/or skill in order to disperse 1,4-butanediol in the form of finer liquid drops. Therefore, only particular technicians can perform the preparation of high active catalysts.
In addition, EP 239,973 and U.S. Pat. No. 4,667,013 above have no disclosure about a catalyst for polymerization of an alkylene oxide, which catalyst is prepared in a reaction field that is a reversed micelle of a W/O system in which the polyhydric alcohol such as 1,4-butanediol is the "water system," and a hydrocarbon solvent is the "oil system."